The present invention is directed to an exhaust adapter for use with a draft inducer of a high-efficiency furnace. More specifically, the present invention is a two-piece stamped metal exhaust adapter configured for attachment to the blower housing of a draft inducer such that the rectangular outlet of the blower housing can be coupled to a round exhaust pipe.
The need to heat structures to control the interior temperature has been a requirement for modern housing for a long time. One of the current popular methods to heat structures is with a furnace that burns either oil or natural gas. Due to the increasing cost of fossil fuels, the operating efficiency of furnaces has become a greater and greater concern.
One method of increasing the fuel efficiency of a burner within a furnace has been to utilize a blower to induce a draft through the furnace to draw the heated air and the products of combustion through a heat exchanger and exhaust them through an exhaust pipe. The blower includes an electric motor and impeller that create a source of negative air pressure such that the heated air and the products of combustion from the burner can travel through as tortured a path as possible to increase the amount of heat removed from the exhaust gases within the heat exchanger. The increase in the flow of air thereby increases the heat transfer and generating capacity of the burner by simultaneously using less fuel per BTU of heat generated.
The addition of a draft inducer to a furnace generates a rating of at least 80% fuel efficiency in a modern furnace. Thus, it is clearly a necessity to introduce a blower to a modern furnace to maintain minimum desired efficiency standards.
Since the introduction of a blower increases the overall cost of a furnace, it is important to manufacture and connect the blower assembly to the furnace in the most effective and efficient manner possible. One common type of blower motor assembly that is currently available is known as a “rectangular exhaust, flush mount blower assembly”. In this type of blower assembly, the blower housing is mounted flush to the furnace, which reduces the space requirement for the blower and provides for easier and more accurate mounting of the blower on the furnace. However, this type of blower assembly has the disadvantage of having a rectangular exhaust outlet. Therefore, to allow the customer to attach the blower assembly to a commonly used round exhaust pipe, a rectangular-to-round exhaust adapter must be used. Typically, the exhaust adapter is formed from cast aluminum, which is expensive to manufacture.
An attempt to address the cost of the exhaust adapter is to use an adapter made out of polymeric material. A polymer exhaust adapter is either injection molded or thermal formed. Polymer exhaust adapters have largely been disregarded because of the inherent problems associated with the use of plastics in the harsh operating environment in which the exhaust adapter is placed. Polymers that are able to withstand the harsh operating environment are very expensive, and even with the use of expensive engineering polymers, there still remains potential problems with durability.
The present invention solves the problems associated with currently available furnace blower motor assemblies with a novel and cost efficient solution. There has been an unrecognized but long felt need in the industry to solve the problems stated above. The present invention solves the above stated problems with an easy to manufacture and assemble solution that has eluded manufacturers for many years.
Accordingly, it is an object of the present invention to provide an exhaust adapter that is inexpensive to manufacture yet durable enough to withstand the harsh operating environment associated with a blower assembly. It is another object of the present invention to provide an exhaust adapter that can be easily attached to the blower housing before the blower housing has been mounted onto the furnace. It is yet another object of the invention to provide a simple, cost effective solution to provide a flush mounted blower assembly with an exhaust adapter to mate with a round exhaust pipe.